Acta Hydrologica Slovaca, Vol. 26, No. 2, 2025, p. 173 - 184, doi: 10.31577/ahs-2025-0026.02.0018
Scientific Paper, English
Priya MISHRA, Sanjeev K. PRASAD: A lightweight hybrid deep learning model for flood risk analysis: A data-driven approach in the Ghaghara River Basin
Full Text in PDF 10 DOWNLOADS
- The Rapti and Ghaghara rivers in northeastern Uttar Pradesh in India are highly flood-prone, causing severe casualties during monsoons. Hence, to enhance flood risk management, this research proposes a hybrid CNN-LSTM model integrated with GIS and remote sensing for flood susceptibility mapping by applying MobileNetV2, a lightweight deep learning model used for efficient feature extraction that optimizes performance without compromising accuracy. The most promising flood-causing factors are identified by using Pareto analysis over conducted expert surveys. The selected factors are drainage density, elevation, slope, land use, rainfall, TWI, and river proximity. The flood susceptibility maps are classified into five classes by all the models: very low, low, moderate, high, and very high. The maps, validated using 2022–2024 flood data, confirm their reliability. The results reveal that the proposed model outperforms CNN and LSTM. This approach enhances flood-prone area assessment, aiding disaster preparedness in the Ghaghara Basin.
KEY WORDS: GIS, CNN, LSTM, MobileNetV2, Remote Sensing
Address:
- Priya MISHRA, School of Computer Science and Engineering, Galgotias University, Gr. Noida, U. P., India (Corresponding author. Tel.: Fax.: Email: amipriya@gmail.com)
- Sanjeev K. PRASAD, School of Computer Science and Engineering, Galgotias University, Gr. Noida, U. P., India
Acta Hydrologica Slovaca, Vol. 26, No. 2, 2025, p. 185 - 194, doi: 10.31577/ahs-2025-0026.02.0019
Review, English
Amel BOUMESSENEGH, Zineb ALLIA: Applied smart hydrology: integration of the GR2M model and machine learning methods in the Oued El Athmania basin (Northeastern Algeria)
Full Text in PDF 3 DOWNLOADS
- Hydrological modeling in semi-arid areas remains difficult due to a lack of data and high spatial and temporal variability. This study proposes a hybrid approach combining the GR2M conceptual model with machine learning algorithms (Random Forest, XGBoost, and Isolation Forest) in Python. Its application to the Oued El Athmania watershed (Algeria) highlights the limitations, but also the relevance, of GR2M alone, with an NSE of 0.836 in calibration and 0.891 in validation. The integration of machine learning significantly improves hydrological forecasts with increased performance (NSE=0.930–0.941; R²=0.933–0.943) and a significant reduction in errors (RMSE, MAE). The Isolation Forest algorithm also demonstrates notable effectiveness in the automatic detection of atypical flows. This combination optimizes both flow forecasting and the anticipation of extreme events. The complementarity between conceptual modeling and data-based approaches thus proves to be a robust solution. It paves the way for smart hydrology that is better adapted to climate uncertainties. Finally, this approach is a strategic tool for sustainable and proactive water resource management in semi-arid contexts.
KEY WORDS: GR2M model; Random Forest; XGBoost; Hybrid modeling; Isolation Forest
Address:
- Amel BOUMESSENEGH, Environmental Engineering and Technology Laboratory University of Mila, LRNAT Natural Hazards and Regional Planning Laboratory, Batna 2, Institute of Science and Technology, University of Abd El Hafid Bouussouf, Mila, Algeria (Corresponding author. Tel.: Fax.: Email: a.boumessenegh@centre-univ-mila.dz)
- Zineb ALLIA, LSNM Natural Sciences and Materials Laboratory University of Mila, Institute of Science and Technology, University Center of Abd El Hafid Bouussouf, Mila, Algeria
Acta Hydrologica Slovaca, Vol. 26, No. 2, 2025, p. 195 - 208, doi: 10.31577/ahs-2025-0026.02.0020
Scientific Paper, English
Zakarya MAOU, Yahyaoui HABIBI, Sami GUELLOUH, Ahmed BOUGHERARA, Billel TOUATI: Impact of dam water impoundment on hydrological regimes and downstream alluvial aquifer recharge: A case study in the Wadi El-Hai Basin, Southeastern Algeria
Full Text in PDF 3 DOWNLOADS
- In arid regions, where water scarcity is a pressing concern, dams are often relied upon to supply water for irrigation, industry, and human consumption. However, these hydraulic structures can have significant negative impacts on downstream hydrological regimes and ecosystems. This research aims to assess the effects of Fountain of Gazelles Dam in southeastern Algeria on the hydrological regime of Wadi El-Hai and the recharge of the Wadi Biskra alluvial aquifer downstream. The study compares historical flow data from Wadi El-Hai before and after the dam's operation, examining the correlation with piezometric fluctuations in the Wadi Biskra alluvial aquifer. A strong positive correlation (0.83) was found between water releases from the dam and rising groundwater levels, indicating that higher releases tend to replenish the aquifer. In contrast, reduced releases lead to a decline in water levels. Groundwater drawdowns of up to 5 meters were observed in the aquifer, reflecting the adverse impact of the dam on recharge. These findings emphasize the critical role of controlled water releases in sustaining groundwater resources. They also highlight the importance of adaptive water management strategies to mitigate the adverse effects on groundwater recharge. By addressing these issues, sustainable water management practices can be implemented to ensure long-term aquifer sustainability in arid regions.
KEY WORDS: dams, hydrological regime, wadis, alluvial aquifer recharge, arid regions, groundwater drawdown
Address:
- Zakarya MAOU, University of Constantine 1, Faculty of Earth Sciences, Geography and Spatial Planning, Laboratory of Territorial Sciences, Natural Resources and Environment ‘Lasterne’, Algeria (Corresponding author. Tel.: Fax.: Email: zakarya.maou@doc.umc.edu.dz)
- Yahyaoui HABIBI, University of Batna 2, Institute of Earth and Universe Sciences, Laboratory of Natural Risks and Territorial, Planning ‘Lrnat’, Algeria
- Sami GUELLOUH, University of Batna 2, Institute of Earth and Universe Sciences, Laboratory of Natural Risks and Territorial, Planning ‘Lrnat’, Algeria
- Ahmed BOUGHERARA, University of Constantine 1, Faculty of Earth Sciences, Geography and Spatial Planning, Laboratory of Territorial Sciences, Natural Resources and Environment ‘Lasterne’, Algeria
- Billel TOUATI, University of Science and Technology of China, School of Earth and Space Sciences, Hefei, 230026, China
Acta Hydrologica Slovaca, Vol. 26, No. 2, 2025, p. 209 - 218, doi: 10.31577/ahs-2025-0026.02.0021
Scientific Paper, English
Krasya KOLCHEVA, Kalin SEYMENOV, Kristina GARTSIYANOVA, Marian VARBANOV, Mariya TEMELKOVA, Miroslava DELIYSKA: Water abstraction and satisfaction of the water needs
in the Topolnitsa River Basin (Southern Bulgaria)
Full Text in PDF 6 DOWNLOADS
- Satisfying water needs under climate change and drought conditions requires current and forecast assessments of available
water resources and their effective allocation and usage, taking into account the level of anthropogenic pressure on water
sources and the degree of water security for users, including ecosystems. This study aims to clarify the level of
anthropogenic pressure from water abstraction on water sources and to assess the degree of water security for users in
the Topolnitsa River Basin (Southern Bulgaria). Based on the water resources system balance with a simulation model
SIMYL, the probability of exceedance by years, months, and volumes in the determined water balance nodes is evaluated.
The pressure from water abstraction is distinguished into four categories from negligible to significant. Results show from
negligible to moderate anthropogenic pressure on the water sources in the upper and lower reaches of the river.
The conducted investigation justifies possible mitigating measures and emphasizes the importance of upgrading and
expanding the research methodology.
KEY WORDS: water abstraction, irrigation, water resource system balance, Topolnitsa River Basin
Address:
- Krasya KOLCHEVA, National Institute of Geophysics, Geodesy and Geography – Hydrology and Water Management Research Center, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 3, Sofia 1113, Bulgaria (Corresponding author. Tel.: Fax.: Email: krasyakolcheva@gmail.com)
- Kalin SEYMENOV, National Institute of Geophysics, Geodesy and Geography – Hydrology and Water Management Research Center, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 3, Sofia 1113, Bulgaria
- Kristina GARTSIYANOVA, National Institute of Geophysics, Geodesy and Geography – Hydrology and Water Management Research Center, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 3, Sofia 1113, Bulgaria
- Marian VARBANOV, National Institute of Geophysics, Geodesy and Geography – Hydrology and Water Management Research Center, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 3, Sofia 1113, Bulgaria
- Mariya TEMELKOVA, National Institute of Geophysics, Geodesy and Geography – Hydrology and Water Management Research Center, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 3, Sofia 1113, Bulgaria
- Miroslava DELIYSKA, National Institute of Geophysics, Geodesy and Geography – Hydrology and Water Management Research Center, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 3, Sofia 1113, Bulgaria
Acta Hydrologica Slovaca, Vol. 26, No. 2, 2025, p. 219 - 225, doi: 10.31577/ahs-2025-0026.02.0022
Scientific Paper, English
Katarína JENEIOVÁ, Lotta BLAŠKOVIČOVÁ, Jana POÓROVÁ: Spatial assessment of areas vulnerable to water shortages in Slovakia
Full Text in PDF 5 DOWNLOADS
- A map of drought prone areas of Slovakia vulnerable to water shortages has been developed by combining the changes in the mean long-term discharges 1991–2020 against the reference period 1961–2000, with the runoff distribution of the period 1961–2000 on the territory of Slovakia. The results of the analysis have been classified into the five categories, with the southern lowlands identified as the most vulnerable and the northern mountainous areas as moderate to low vulnerability areas. The observed changes are based on the mean long-term discharges, with low flows requiring a further analysis. Despite the limitations, including the exclusion of groundwater impact, the maps at the district level resolution provide a practical tool for water planning, resource management, and decision-making at a district level for drought mitigation.
KEY WORDS: long-term discharge changes, spatial analysis, water planning
Address:
- Katarína JENEIOVÁ, Slovak Hydrometeorological Institute, Jeséniova 17, 833 15 Bratislava, Slovak Republic (Corresponding author. Tel.: Fax.: Email: katarina.jeneiova@shmu.sk)
- Lotta BLAŠKOVIČOVÁ, Slovak Hydrometeorological Institute, Jeséniova 17, 833 15 Bratislava, Slovak Republic
- Jana POÓROVÁ, Slovak Hydrometeorological Institute, Jeséniova 17, 833 15 Bratislava, Slovak Republic
Acta Hydrologica Slovaca, Vol. 26, No. 2, 2025, p. 226 - 235, doi: 10.31577/ahs-2025-0026.02.0023
Scientific Paper, English
Zuhriddin JURAEV, Mirzohid KORIYEV, Ikboljon SOLIEV: Six decades of climate and water variability in the Sokh Basin of Central Asia
Full Text in PDF 5 DOWNLOADS
- This study examines how long-term climate variability has affected surface and groundwater resources in the Sokh Basin,
a key agricultural region of the Fergana Valley in Uzbekistan. Using data from 1961 to 2020, we found that total annual
precipitation varied considerably from year to year but showed no consistent long-term trend. In contrast, mean annual
temperatures increased steadily by about 0.03°C per year, confirming a clear regional warming trend. River discharge in
the Sokh also increased over time, by about 0.23 m³ per second each year, most likely due to earlier snowmelt and greater
runoff during warmer springs. Groundwater levels responded unevenly across the basin: three monitoring wells remained
stable, while one (Well 258) showed a marked decline of about 5 cm per year, reflecting localised overuse and limited
recharge. These findings demonstrate that even modest climatic warming can produce complex and uneven water
responses. The results highlight the need for site-specific monitoring and adaptive water management to sustain agriculture
and groundwater resources in semi-arid, snow-dependent regions facing ongoing climate change.
KEY WORDS: Climate variability; Groundwater trends; River discharge; Sokh Basin; Central Asia
Address:
- Zuhriddin JURAEV, Department of Geography, Chonnam National University, Buk-Gu, Yongbong-ro 77, Gwangju 61186, Republic of Korea (Corresponding author. Tel.: Fax.: Email: david94@jnu.ac.kr)
- Mirzohid KORIYEV, Department of Natural Sciences, Namangan State Pedagogical Institute, Uychi Street 316, Namangan 160107, Uzbekistan
- Ikboljon SOLIEV, Department of Geography and Environmental Protection, Namangan State University, Uychi Street 316, Namangan 160107, Uzbekistan
Acta Hydrologica Slovaca, Vol. 26, No. 2, 2025, p. 236 - 243, doi: 10.31577/ahs-2025-0026.02.0024
Scientific Paper, English
Michal DANKO, Martin JANČO, Patrik SLEZIAK, Soňa LIOVÁ: Climatic and hydrological characteristics of the mountain catchment:
A comparison of the current period with the 30-year normal
Full Text in PDF 3 DOWNLOADS
- The research base for mountain hydrology at the Institute of Hydrology of the Slovak Academy of Sciences has been
conducting a study of water balance components in the Jalovecký Creek catchment since 1986. The primary objective of
this study is to evaluate the meteorological and hydrological data for the period 1986 – 2025 within the Jalovecký Creek
catchment, which serves as a representative basin for the hydrological cycle of the mountain part of the Western Tatras.
The main motivation was to analyse air temperature, precipitation, snow water equivalent (SWE), and runoff coefficient
from the catchment in the current period and compare them with the 30-year normal (1991–2020). Based on these data,
the maximum and minimum values of air temperature, precipitation intensity, and SWE for the observed period were also
analysed. The paper also evaluates the years in which the minimum precipitation threshold (300 mm) required for
the optimal development of Norway spruce (Picea abies) during the growing season was not met. At an altitude of 750 m
a.s.l., where spruce monocultures are located, the spruce is most vulnerable to precipitation deficit. In contrast, no
precipitation deficit has been recorded at the altitude of 1,500 m a.s.l. to date. According to the World Meteorological
Organization, the year 2024 was one of the warmest on a global scale. Therefore, we aimed to ascertain whether
temperature records were also observed at our monitoring stations. A record high annual air temperature of 9.9°C was
confirmed at the Liptovská Ondrašová station (570 m a.s.l.), representing the highest annual temperature since
the beginning of observations in 1986. However, the air temperature record was not surpassed at the Červenec station
(1,500 m a.s.l.) in the mountain part of the catchment. Based on the analysis of annual precipitation in the submontane
and mountain parts of the catchment, the long-term trend does not indicate a significant increase or decrease. The last two
years evaluated, 2024 and 2025, showed substantial differences in the amount of precipitation during the winter months
(774 mm in the 2023/2024 season vs. 251 mm in the 2024/2025 season). In the current period, a precipitation deficit of
approximately 30% relative to the 30-year normal is observed. The runoff coefficient remains stable in the mountain part
of the catchment during the hydrological years (1989–2024), but it shows a decreasing trend for the entire catchment area
KEY WORDS: rainfall, snow pack, Norway spruce, runoff coefficient
Address:
- Michal DANKO, Institute of Hydrology SAS, Dúbravská cesta 9, 841 04 Bratislava, Slovak Republic
- Martin JANČO, Institute of Hydrology SAS, Dúbravská cesta 9, 841 04 Bratislava, Slovak Republic (Corresponding author. Tel.: Fax.: Email: janco@uh.savba.sk)
- Patrik SLEZIAK, Institute of Hydrology SAS, Dúbravská cesta 9, 841 04 Bratislava, Slovak Republic
- Soňa LIOVÁ, Slovak Hydrometeorological Institute, Bôrická cesta 103, 011 13 Žilina, Slovak Republic
Acta Hydrologica Slovaca, Vol. 26, No. 2, 2025, p. 244 - 256, doi: 10.31577/ahs-2025-0026.02.0025
Scientific Paper, English
Dana HALMOVÁ, Veronika BAČOVÁ MITKOVÁ: Temporal variability and autoregressive modeling of key water quality parameters in the Hron River basin
Full Text in PDF 1 DOWNLOADS
- The Hron River basin is considered as an important hydrological region in Slovakia and plays a key role in regional water
management, agriculture, and biodiversity conservation. In our study, we focused on analyzing the long-term trends of
key physico-chemical parameters of surface water quality like dissolved oxygen (DO), biochemical oxygen demand
(BOD), water temperature (Tw), and acidity (pH), which provide critical insights into water quality and the ecological
status of aquatic ecosystems. Climate changes are contributing to rising river water temperatures, leading to decreased
DO levels due to reduced oxygen solubility and increased biological oxygen demand. The first part of this study was
dedicated to trend analysis of long-term time series of the aforementioned surface water quality parameters at two
monitoring sites along the Hron River: Kamenica nad Hronom (1992–2021) and Valaská (1974–2021). At the Kamenica
nad Hronom, the analysis of monthly and annual data revealed decreasing trends in BOD and pH values during certain
months, particularly in the summer period. At the Valaská, values of pH indicates an increasing trend during the
hydrological year and significant increasing long-term trend in June, November and annual data. In the second part of the
study, selected water quality parameters at the Valaská and Kamenica nad Hronom were modelled using an autoregressive
integrated moving average model. The selected ARIMA model effectively simulated variations in the monthly
concentrations/values of the chosen physico-chemical parameters and was subsequently used to predict future trends in
surface water quality in the region.
KEY WORDS: water quality parameters, long-term trend, autoregressive modelling, ARIMA model, prediction
Address:
- Dana HALMOVÁ, Institute of Hydrology SAS, Dúbravská cesta 9, 841 04 Bratislava, Slovak Republic (Corresponding author. Tel.: Fax.: Email: halmova@uh.savba.sk)
- Veronika BAČOVÁ MITKOVÁ, Institute of Hydrology SAS, Dúbravská cesta 9, 841 04 Bratislava, Slovak Republic
Acta Hydrologica Slovaca, Vol. 26, No. 2, 2025, p. 257 - 267, doi: 10.31577/ahs-2025-0026.02.0026
Scientific Paper, English
Milan GOMBOŠ, Andrej TALL, Branislav KANDRA, Dana PAVELKOVÁ: Effect of gypsum application on soil water retention and moisture dynamics
Full Text in PDF 1 DOWNLOADS
- Climate change has increased the frequency of droughts, highlighting the importance of measures that promote soil water
retention. Gypsum (CaSO₄·2H₂O) is a widely used soil amendment with the ability to improve aggregate stability and
infiltration. This study evaluated the effect of the application of calcium sulphate dihydrate on soil volumetric moisture
using two experimental approaches. A short-term experiment in the surface layer (0–10 cm) did not reveal significant
differences in the average moisture content, but higher doses of gypsum led to greater variability and the appearance of
extreme values. Long-term monitoring of the soil profile (0–30 cm) demonstrated a positive and gradually increasing
effect of gypsum on water retention, especially at a dose of 4 t ha⁻¹, which maintained moisture in the optimal range
available to plants throughout the growing season. Comparisons with soil hydrolimits showed that gypsum application
extended the period during which soil water was available to plants. The results suggest that gypsum can be an effective
land improvement measure to improve the soil water regime and increase the resistance to drought in Central European
conditions.
KEY WORDS: calcium sulfate dihydrate, soil moisture, soil hydrolimits, water retention, drought resistance
Address:
- Milan GOMBOŠ, Institute of Hydrology SAS, Dúbravská cesta 9, 841 04 Bratislava, Slovak Republic (Corresponding author. Tel.: Fax.: Email: gombos@uh.savba.sk)
- Andrej TALL, Institute of Hydrology SAS, Dúbravská cesta 9, 841 04 Bratislava, Slovak Republic
- Branislav KANDRA, Institute of Hydrology SAS, Dúbravská cesta 9, 841 04 Bratislava, Slovak Republic
- Dana PAVELKOVÁ, Institute of Hydrology SAS, Dúbravská cesta 9, 841 04 Bratislava, Slovak Republic
Acta Hydrologica Slovaca, Vol. 26, No. 2, 2025, p. 268 - 279, doi: 10.31577/ahs-2025-0026.02.0027
Scientific Paper, English
Milan ONDERKA, Dalibor VÝBERČI, Roman VÝLETA, Silvia KOHNOVÁ: Design rainfall intensities in Slovakia: Historical evolution of estimation methods and challenges under a changing climate
Full Text in PDF 1 DOWNLOADS
- Design rainfall intensities are a key input for hydrological design, particularly in urban drainage planning. They also play
a crucial role in flood protection, water management, and the design of sustainable and green infrastructure, making their
accurate estimation essential for both economic efficiency and public safety. This paper reviews the methods used to
derive rainfall design values in the territory of modern-day Slovakia over more than a century, drawing on the recent and
historical contributions. It also describes the historical evolution of rainfall measuring instruments, from early mechanical
ombrographs to modern automatic rain gauges, which formed the foundation for quantitative analysis of rainfall
intensities. Early empirical efforts in the late 19th and early 20th centuries were closely tied to sewer-network design and
relied on simplified formulas and limited observations. A major methodological shift occurred in the mid-20th century
with the adoption of statistical frequency analysis, which introduced a rigorous probabilistic framework for estimating
rainfall extremes. Recent progress has been enabled by digitized records, high-resolution automatic rain gauges, and
advanced statistical methods, including Bayesian inference that allow explicit quantification of uncertainty. Modern
methods combine regional frequency analysis with gridded products from reanalyses and climate models. There is
an urgent need to adapt design methods to the ongoing climate change and an inherently non-stationary climate system.
Regional climate models are increasingly used to estimate future rainfall extremes, since reliance on historical
observations alone is no longer sufficient for planning and designing long-lived infrastructure. However, no universally
recognized methodology has yet been endorsed, leaving national agencies and researchers to develop approaches tailored
to local needs and data availability. This review provides a systematic overview that connects historical, current, and
future perspectives.
KEY WORDS: design rainfall intensities; IDF curves; frequency analysis; regional frequency analysis; climate change
Address:
- Milan ONDERKA, Regional Climatological Institute, 900 68 Plavecký Štvrtok 794, Slovakia (Corresponding author. Tel.: Fax.: Email: m.onderka@regioclim.eu)
- Dalibor VÝBERČI, Regional Climatological Institute, 900 68 Plavecký Štvrtok 794, Slovakia
- Roman VÝLETA, Department of Land and Water Resources Management, Faculty of Civil Engineering, Slovak University of Technology in Bratislava, Radlinského 11, 810 05 Bratislava, Slovakia
- Silvia KOHNOVÁ, Department of Land and Water Resources Management, Faculty of Civil Engineering, Slovak University of Technology in Bratislava, Radlinského 11, 810 05 Bratislava, Slovakia
Acta Hydrologica Slovaca, Vol. 26, No. 2, 2025, p. 280 - 291, doi: 10.31577/ahs-2025-0026.02.0028
Scientific Paper, English
Marián MELO, Filip CZUCZOR, Pavla PEKÁROVÁ, Katarína MELOVÁ, Adam RUSINKO, Martin GERA: The severe ice flood of 1876 on the Nitra River in Nové Zámky, in the context of other floods in the Danubian Lowland, Slovakia
Full Text in PDF DOWNLOADS
- While studying historical floods on the Nitra River, we encountered a reference in period newspapers to a commemorative plaque that marked a significant flood event in 1876 in the town of Nové Zámky. Our research aimed to identify the original location of this plaque in Nové Zámky and to gather more detailed information about this major flood. We found that floods occurred simultaneously in several other rivers and locations across the Danubian Lowland in Slovakia. Through climatological assessments and analyses of historical documents, we were able to determine the causes, timing, and, most-importantly, the extent of the damage caused by these floods. Our findings was classified the ice flood of 1876 on the Nitra River as a level 3 flood event, representing the highest intensity category
KEY WORDS: ice flood, documentary data, climatological data, Nitra River, flood mark
Address:
- Marián MELO, Comenius University Bratislava, Faculty of Mathematics, Physics and Informatics, Mlynská dolina, 842 48 Bratislava, Slovak Republic (Corresponding author. Tel.: Fax.: Email: Marian.Melo@fmph.uniba.sk)
- Filip CZUCZOR, Comenius University Bratislava, Faculty of Natural Sciences, Department of Physical Geography and Geoinformatics, Mlynská dolina, Ilkovičova 6, 842 15 Bratislava, Slovak Republic
- Pavla PEKÁROVÁ, Institute of Hydrology SAS, Dúbravská cesta 9, 841 04 Bratislava, Slovak Republic
- Katarína MELOVÁ, Slovak Hydrometeorological Institute, Jeséniova 17, 833 15 Bratislava, Slovak Republic
- Adam RUSINKO, Comenius University Bratislava, Faculty of Natural Sciences, Department of Physical Geography and Geoinformatics, Mlynská dolina, Ilkovičova 6, 842 15 Bratislava, Slovak Republic
- Martin GERA, Comenius University Bratislava, Faculty of Mathematics, Physics and Informatics, Mlynská dolina, 842 48 Bratislava, Slovak Republic
Acta Hydrologica Slovaca, Vol. 26, No. 2, 2025, p. 292 - 297, doi: 10.31577/ahs-2025-0026.02.0029
Scientific Paper, English
Martina ZELEŇÁKOVÁ, Tatiana SOĽÁKOVÁ, Kristián MIČKO, Patrik NAGY, Hany F. ABD-ELHAMID, Helena HLAVATÁ: Temporal evolutionary precipitation trends in Košice city under different scenarios of greenhouse emission
Full Text in PDF DOWNLOADS
- The rising levels of greenhouse gases (GHGs) in the atmosphere are causing an increase in air temperature and altering
the precipitation patterns. Over the past 138 years, the air temperature in Slovakia has risen by 1.7 to 1.8°C, and
the frequency of extreme weather events has also increased. This study analyses the future changes in precipitation (2021–
2099) under the representative concentration pathways (RCP2.6 and RCP8.5) for the city of Košice at a monthly scale
relative to the observed historical period from 1972 to 2020. The significance of the projected changes was assessed at
a 95% confidence level using the Mann-Kendall test. The primary benefit of this study is identifying changes in
precipitation and their trends under different greenhouse gasses emission scenarios, with the goal of preparing for
phenomena like drought and floods in the observation city. According to the lowest emission scenarios RCP 2.6, we can
expect periods with the lowest precipitation in the hydrological years; 2058, 2074, 2092 and periods with the highest
precipitation will be at; 2029, 2046, 2047, 2049, 2061, 2065, 2079. Under the most severe emission scenario RCP 8.5,
the periods of lowest precipitation are projected to occur in 2082 and 2097, while the periods of highest precipitation are
expected in 2047 and 2068.
KEY WORDS: greenhouse gases emissions (GHGs), precipitation trends, Mann-Kendal test, representative concentration pathways (RCP2.6 and RCP8.5)
Address:
- Martina ZELEŇÁKOVÁ, Faculty of Civil Engineering, Technical University of Košice, Vysokoškolská 4, 040 01 Košice, Slovak Republic (Corresponding author. Tel.: Fax.: Email: martina.zelenakova@tuke.sk)
- Tatiana SOĽÁKOVÁ, Faculty of Civil Engineering, Technical University of Košice, Vysokoškolská 4, 040 01 Košice, Slovak Republic
- Kristián MIČKO, Faculty of Civil Engineering, Technical University of Košice, Vysokoškolská 4, 040 01 Košice, Slovak Republic
- Patrik NAGY, Faculty of Civil Engineering, Technical University of Košice, Vysokoškolská 4, 040 01 Košice, Slovak Republic
- Hany F. ABD-ELHAMID, Zagazing University, Zagazing 44519, Egypt
- Helena HLAVATÁ, Slovak Hydrometeorological Institute, Regional Office Košice, Ďumbierska 26, 041 17 Košice, Slovak Republic
Acta Hydrologica Slovaca, Vol. 26, No. 2, 2025, p. 298 - 305, doi: 10.31577/ahs-2025-0026.02.0030
Scientific Paper, English
Radoslav SCHÜGERL: Comparison of different approaches for determining of the roughness coefficient during the growing season
Full Text in PDF 1 DOWNLOADS
- This article compares several different methods used for estimating the Manning roughness coefficient of a reach using
observed conditions during growing season. A survey was taken of the Malina River in south-west part of Slovakia.
The survey included 4 cross sections profiles (two sections), water surface slope, and flow velocity readings at each cross
section profile. These hydraulic characteristics, were used to calculate the roughness coefficient of the reach.
Measurements were taken end of February and beginning of September. This value was then compared to a empirical
method, when were used fifteen equations from differente authors. Field measurements collected during the growing
season demonstrated that vegetation density significantly influences flow velocity and roughness coefficients. Knowledge
of the granulometric compose from riverbed sediment and water level surface was necessary for the calculation for
roughness coefficient. Empirical equations exhibited limited predictive capability in lowland streams with, while the direct
measurements produced more accurate estimates. Empirical equations are suitable for use in winter, respectively early
spring season.
KEY WORDS: aquatic vegetation, empirical equations, grain-size curve, hydraulic resistance, roughness coefficient
Address:
- Radoslav SCHÜGERL, Institute of Hydrology SAS, Dúbravská cesta 9, 841 04 Bratislava, Slovak Republic (Corresponding author. Tel.: Fax.: Email: schugerl@uh.savba.sk)
Acta Hydrologica Slovaca, Vol. 26, No. 2, 2025, p. 306 - 317, doi: 10.31577/ahs-2025-0026.02.0031
Scientific Paper, English
Ognjen BONACCI, Ana ŽAKNIĆ-ĆATOVIĆ, Tanja ROJE-BONACCI: Detecting subtle hydrological changes in a small basin in a changing climate:
The Bednja River case
Full Text in PDF 2 DOWNLOADS
- This study examines the hydrological regime of the Bednja River at the Ludbreg gauging station on an annual timescale.
In addition to the series of mean annual discharges at Ludbreg for the period 1947–2023, the study also analyzes annual
precipitation and mean annual air temperature series measured at the Ludbreg climatological station for the period 1982–
2024. The mean annual discharge series exhibits a statistically insignificant decreasing trend, while the annual
precipitation series shows a statistically insignificant increasing trend. In contrast, the mean annual air temperature series
reveals a statistically significant increasing trend. Annual runoff coefficients were calculated for the 1982–2023 period
and display a decreasing but statistically insignificant trend. The study also computed annual values for three drought
indices: (1) the Standardized Discharge Index (SQI); (2) the Standardized Precipitation Index (SPI); and (3) the New
Drought Index (NDI). The SQI shows a statistically insignificant decreasing trend, the SPI a statistically insignificant
increasing trend, while the NDI reveals a statistically significant decreasing trend, indicating a notable intensification of
drought conditions in the Bednja catchment. Despite stable precipitation levels, rising air temperature contributes to
reduced streamflow and increased hydrological vulnerability across the entire catchment. The NDI stands out as the most
sensitive drought indicator and may serve as a useful tool in planning climate change adaptation measures in small
catchments
KEY WORDS: discharge, air temperature, drought, runoff coefficient, Bednja River
Address:
- Ognjen BONACCI, Faculty of Civil Engineering, Architecture and Geodesy Split University, Matice Hrvatske 15, 21000 Split, Croatia
- Ana ŽAKNIĆ-ĆATOVIĆ, University of Toronto Scarborough, Department of Physical and Environmental Sciences, 1065 Military Trail, Toronto, ON, M1C 1A4, Canada (Corresponding author. Tel.: Fax.: Email: ana.zaknic.catovic@utoronto.ca)
- Tanja ROJE-BONACCI, Faculty of Civil Engineering, Architecture and Geodesy Split University, Matice Hrvatske 15, 21000 Split, Croatia
Acta Hydrologica Slovaca, Vol. 26, No. 2, 2025, p. 318 - 326, doi: 10.31577/ahs-2025-0026.02.0032
Scientific Paper, English
Patrik SLEZIAK, Michal DANKO, Martin JANČO, Ladislav HOLKO, Viera RATTAYOVÁ: Estimation of actual evapotranspiration in a mountain catchment using distributed hydrological models and satellite data
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- Actual evapotranspiration (AET) is one of the fundamental components of the water balance. At the catchment scale, it is
typically determined from the hydrological balance or by modelling. Vegetation changes, such as forest dieback or forest
harvesting, can significantly affect the AET, but the extent of these changes is not well known. This work aims to (a)
compare the AET calculated using two different modelling approaches and satellite data in a mountain catchment
(the Jalovecký Creek catchment in the West Tatras) that is undergoing natural dieback and forest regeneration, and (b)
evaluate changes in the water balance of the catchment. Satellite evapotranspiration datasets (GLEAM versions 3.5b and
4.2a, GLDAS) and reanalysis-based products (ERA5 and MERRA-2) were utilized. Two distributed hydrological models,
WaSiM and MIKE SHE, were used to model the AET. Daily data (precipitation, air temperature, air humidity, wind speed,
solar radiation) from hydrological years 2013 (original forest state) to 2022 (altered forest) were used as input data for the
models. The calculation of potential evapotranspiration (PET) in the WaSiM model is based on the Penman-Monteith
method, while the MIKE SHE model uses the Blaney-Criddle method. Each model has a parameterization allowing
the calculation of AET for the vegetation classes present in the study catchment (spruce forest, dwarf pine, alpine
meadows). Due to the ongoing forest dieback and regeneration, the models were deliberately calibrated for each year of
the study period. The results showed that both models overestimated the average annual AET calculated from measured
precipitation and runoff. The highest AET values were simulated for the spruce forest, the lowest for the alpine meadows.
AET estimates derived from the reanalyses and satellite products exhibited reduced interannual variability compared to
that based on the hydrological balance. ERA5 systematically underestimated monthly AET by up to 40% in comparison
with other datasets, whereas MERRA2 consistently yielded values at the upper range, exceeding ERA5 by approximately
30–40% during summer.
KEY WORDS: water balance, vegetation zones, hydrological modelling, remote sensing datasets, mountain environment
Address:
- Patrik SLEZIAK, Institute of Hydrology SAS, Dúbravská cesta 9, 841 04 Bratislava, Slovak Republic (Corresponding author. Tel.: Fax.: Email: sleziak@uh.savba.sk)
- Michal DANKO, Institute of Hydrology SAS, Dúbravská cesta 9, 841 04 Bratislava, Slovak Republic
- Martin JANČO, Institute of Hydrology SAS, Dúbravská cesta 9, 841 04 Bratislava, Slovak Republic
- Ladislav HOLKO, Institute of Hydrology SAS, Dúbravská cesta 9, 841 04 Bratislava, Slovak Republic
- Viera RATTAYOVÁ, Slovak Hydrometeorological Institute, Climatological Service Department, Jeséniova 17, 833 15 Bratislava, Slovak Republic
Acta Hydrologica Slovaca, Vol. 26, No. 2, 2025, p. 327 - 336, doi: 10.31577/ahs-2025-0026.02.0033
Scientific Paper, English
Marek SOKÁČ, Márta KOCZKA BARA, Yvetta VELÍSKOVÁ: Transformation of rainfall time series for the assessment of infrastructure measures taking into account climate change
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- In addressing water management challenges, a model-based evaluation of infrastructure design or operational measures
is frequently required, assessing functionality of proposed measures under various operational conditions in the future.
This approach requires additional input data to facilitate long-term numerical simulations of efficiency and suitability of
the infrastructure design. For instance, in urban drainage, this comprises rain gauge data, particularly long-term time series
data. Given the infrastructure's lifespan, it is imperative to consider its anticipated evolution, including the effects of
climate change on precipitation.
In this paper, we propose a methodology for transforming existing rainfall data into a long-term rainfall time series, with
parameters defined based on projected climate change. The statistical analysis of the transformed series confirms
the ability of the numerical transformation method and the viability of utilising the transformed time series for drainage
infrastructure design assessment through numerical simulation models.
KEY WORDS: time series, rain gauge data, climate change, transformation
Address:
- Marek SOKÁČ, Institute of Hydrology SAS, Dúbravská cesta 9, 841 04 Bratislava, Slovak Republic (Corresponding author. Tel.: Fax.: Email: sokac@uh.savba.sk)
- Márta KOCZKA BARA, Institute of Hydrology SAS, Dúbravská cesta 9, 841 04 Bratislava, Slovak Republic
- Yvetta VELÍSKOVÁ, Institute of Hydrology SAS, Dúbravská cesta 9, 841 04 Bratislava, Slovak Republic
Acta Hydrologica Slovaca, Vol. 26, No. 2, 2025, p. 337 - 346, doi: 10.31577/ahs-2025-0026.02.0034
Scientific Paper, English
Michaela DANÁČOVÁ, Esmaeil JEIHOUNI, Tomáš BACIGÁL, Roman VÝLETA, Zuzana DANÁČOVÁ, Ján SZOLGAY: Travel-time–discharge modelling for flood routing with broken line regression on the Morava River
Full Text in PDF DOWNLOADS
- The paper contributes to the development of a multilinear discrete cascade flood routing model whose parameters adjust
to discharge-dependent changes in peak travel time. The nonlinear dependence of flood peak travel time on discharge is
modelled by a broken line piecewise linear relationship. The parameters of this model were estimated using segmented
nonlinear regression, in which the breakpoints of the broken line are treated as actual parameters through simple
linearization within a linear-predictor framework. The model was fitted to empirical travel-time data to quantify
the transitions in flood wave attenuation regimes on the Morava River. The fitted model shows an increasing wave speed
when the discharge rises in the channel and post-bankfull deceleration when floodplain storage is activated. The segmented
broken-line relationship is embedded in the discrete state-space form of the Kalinin–Miljukov model, as discharge-driven
control is employed in flood routing. The framework is presented as general and transferable to other rivers exhibiting
complex inundation dynamics. A model application on the Morava River yielded satisfactory accuracy in predicting flood
propagation
KEY WORDS: flood wave routing; piecewise liner travel time–discharge relationship; segmented nonlinear regression; Kalinin–Miljukov model; Morava River (Slovakia)
Address:
- Michaela DANÁČOVÁ, Department of Land and Water Resources Management, Faculty of Civil Engineering, Slovak University of Technology in Bratislava, Radlinského 11, 810 05 Bratislava, Slovak Republic (Corresponding author. Tel.: Fax.: Email: michaela.danacova@stuba.sk)
- Esmaeil JEIHOUNI, Department of Mathematics and Descriptive Geometry, Faculty of Civil Engineering, Slovak University of Technology in Bratislava, Radlinského 11, 810 05 Bratislava, Slovak Republic
- Tomáš BACIGÁL, Department of Mathematics and Descriptive Geometry, Faculty of Civil Engineering, Slovak University of Technology in Bratislava, Radlinského 11, 810 05 Bratislava, Slovak Republic
- Roman VÝLETA, Department of Land and Water Resources Management, Faculty of Civil Engineering, Slovak University of Technology in Bratislava, Radlinského 11, 810 05 Bratislava, Slovak Republic
- Zuzana DANÁČOVÁ, Slovak Hydrometeorological Institute, Department Quantity of Surface Water, Jeséniova 17, 833 15 Bratislava, Slovak Republic
- Ján SZOLGAY, Department of Land and Water Resources Management, Faculty of Civil Engineering, Slovak University of Technology in Bratislava, Radlinského 11, 810 05 Bratislava, Slovak Republic
Acta Hydrologica Slovaca, Vol. 26, No. 2, 2025, p. 347 - 357, doi: 10.31577/ahs-2025-0026.02.0035
Scientific Paper, English
Mehdi KEBLOUTI, Bojan ĐURIN, Mohamed Walid AZIZI, Durga SHARMA, Soraya BOUSLAH, Rayane SACI, Kenza BOUALI, Faiza BOUZAHAR, Mohamed Amine HABBACHE: Comparative study between classical methods and machine learning models to estimate missing monthly rainfall, case of Coastal Oranians Center watershed
Full Text in PDF DOWNLOADS
- The accurate estimate of missing rainfall data is essential for hydrological modeling, climate research, and water resource
management. This study evaluates and compares the effectiveness of conventional interpolation techniques. Using
machine learning (ML) techniques to predict missing monthly rainfall data in the coastal Oranians center watershed,
Algeria. Four classical methods, such as linear regression, inverse distance weighting (IDW), spline interpolation, and
local polynomial interpolation, were assessed alongside four ML models: Multilayer Perceptron (MLP), Modified Nearest
Neighbor (MNN), Normalized Nearest Neighbor (NNN), and Least Squares Support Vector Machine (LSVM). Several
statistical metrics, including RMSE, MAE, MRE, R
2
, and Taylor diagrams, were used to assess the models and conduct
comparative analysis. LSVM has the maximum performance (R
2=0.99, RMSE=9.13), according to the data, which implies
that ML models exhibit superior performance compared to conventional methodologies. Even though local polynomial
interpolation was less accurate than machine learning models, it was still superior to traditional techniques. These results
suggest that incomplete rainfall datasets can be enhanced by AI-driven techniques, making them suitable for use in
environmental and hydrological studies.
KEY WORDS: Algeria, machine learning, monthly precipitation, spatial interpolation methods, missing data
Address:
- Mehdi KEBLOUTI, Department of Hydraulic, Faculty of Technology, Badji Mokhtar-Annaba University, P.O. Box 12, 23000, Annaba, Algeria (Corresponding author. Tel.: Fax.: Email: mehdi.keblouti@univ-annaba.dz)
- Bojan ĐURIN, Department of Civil Engineering, University North, Jurja Križanića 31b, 42000 Varaždin, Croatia
- Mohamed Walid AZIZI, Environmental Engineering and Technology Laboratory, Abdelhafid Boussouf University Center, P.O. Box 26, 43000, Mila, Algeria
- Durga SHARMA, Impact Hub Hyderabad, University of Hyderabad, 1st Floor, C9MQ+G2V A&A Lakefront, opposite to Durgam Cheruvu Lake, Software Units Layout, Madhapur, Hyderabad, Telangana 500081, India
- Soraya BOUSLAH, Laboratory of Soils and Hydraulic, Department of Hydraulic, Faculty of Technology, Badji Mokhtar-Annaba University, P.O. Box 12, 23000, Annaba, Algeria
- Rayane SACI, Geology Research Laboratory (GRL), Department of Geology, Faculty of Earth Sciences, Badji Mokhtar-Annaba University, P.O. Box 12, 23000, Annaba, Algeria
- Kenza BOUALI, Environmental Engineering and Technology Laboratory, Abdelhafid Boussouf University Center, P.O. Box 26, 43000, Mila, Algeria
- Faiza BOUZAHAR, Kasdi Merbah University, Ouargla Ghardaia Road, BP. 511, 30,000, Algeria
- Mohamed Amine HABBACHE, Department of Hydraulic, Faculty of Technology, Badji Mokhtar-Annaba University, P.O. Box 12, 23000, Annaba, Algeria
Acta Hydrologica Slovaca, Vol. 26, No. 2, 2025, p. 358 - 365, doi: 10.31577/ahs-2025-0026.02.0036
Scientific Paper, English
Lucia TOKOVÁ, Csilla FARKAS, Dušan IGAZ: Analysis of soil water regime in the soil with applied biochar using field scale hydrological model SWAP
Full Text in PDF DOWNLOADS
- The main objective of this study was to analyze the impact of the biochar application on the soil water regime
using the SWAP hydrological model. To reach this goal we will calibrate a field–scale model SWAP based on the existing
data from a biochar field experiment located in Dolná Malanta (Nitra, Slovakia). The statistical analysis was conducted
by the model sensitivity analysis (index of agreement, Nash Sutcliffe efficiency and percent bias/deviation). Index of
agreement (d) was 0.938 and 0.933 for Control (pure silty loam soil) and B20 (treatment with applied biochar in the rate
of 20 t ha–1
), respectively. Results of the sensitivity analysis also demonstrated that the model had reliable sensitivity to
daily precipitation changes. The simulated water regime corresponds to the observed data of soil moisture and it was
higher on the treatment with applied biochar (B20) during the whole simulation period (from April to September 2019)
associated with the higher water storage on B20 treatment
KEY WORDS: SWAP model, model calibration, biochar amended soil, water storage
Address:
- Lucia TOKOVÁ, Institute of Hydrology SAS, Dúbravská cesta 9, 841 04 Bratislava, Slovak Republic (Corresponding author. Tel.: Fax.: Email: tokova@uh.savba.sk)
- Csilla FARKAS, Division of Environment and Natural Resources, Norwegian Institute of Bioeconomy Research, Oluf Thesens vei 43
1433 As, Norway
- Dušan IGAZ, Institute of Landscape Engineering, Slovak University of Agriculture, Hospodárska 7, 949 76 Nitra, Slovak Republic
Acta Hydrologica Slovaca, Vol. 26, No. 2, 2025, p. 366 - 378, doi: 10.31577/ahs-2025-0026.02.0037
Scientific Paper, English
Laounia NEHAL, Khadidja SEMARI, Malika ABBES, Naouel BOUREGBA: Drought study in the Macta watershed (North West of Algeria) using Standardized Precipitation Index (SPI)
Full Text in PDF DOWNLOADS
- Drought is a persistent challenge in Mediterranean regions, particularly in Algeria, which has endured several intense
drought episodes over recent decades. These events have significantly affected both the environment and the country's
economy. This study focuses on analyzing drought patterns across space and time within the Macta watershed. First, we
identified the most homogeneous observation period (1969–2011) by applying homogeneity tests to data from 42 rainfall
stations. This allowed for a consistent assessment of drought evolution using the 12-month Standardized Precipitation
Index (SPI-12). The analysis revealed that the most significant drought events occurred between 1980 and 1990 and
persisted into the mid-2000s. Dry episodes peaked in 1981, when 31 stations reported severe drought conditions. Other
notable years include 1992, 1999, 1996, 1988, 1998, 1983, 1989, and 1993. Overall, droughts in the 1980s were more
intense than those in the 1990s. In the 21st century, two major droughts were identified in 2004 and 2007, as evidenced
by the spatial distribution of severity levels.
KEY WORDS: drought; SPI; GIS; Macta watershed; Algeria
Address:
- Laounia NEHAL, Research on Biological Systems and Geomatics Laboratory, University Mustapha Stambouli of Mascara, BP 305 Mamounia, 29000, Mascara, Algeria
- Khadidja SEMARI, Laboratory of Water Sciences and Techniques, University Mustapha Stambouli of Mascara, BP 305 Mamounia Street, 29000, Mascara, Algeria (Corresponding author. Tel.: Fax.: Email: khadidja@yahoo.fr)
- Malika ABBES, Hydrometeorological Institute for Training and Research, Bp 7019 Ibnou Rochd, Oran, Algeria
- Naouel BOUREGBA, Laboratory of Water Sciences and Techniques, University Mustapha Stambouli of Mascara, BP 305 Mamounia Street, 29000, Mascara, Algeria
Acta Hydrologica Slovaca, Vol. 26, No. 2, 2025, p. 379 - 386, doi: 10.31577/ahs-2025-0026.02.0038
Scientific Paper, English
Bahija CHOUKRI, Omaima ELKBICHI, Elhoucein LAYATI, Mohamed EL GHACHI: Detecting shifts in low-flow regimes using QMNA and CUSUM analysis under climate
pressure: A 55-year case study from the Oued Reghaya watershed (Tensift, Morocco)
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- This study investigates the long-term dynamics of low-flow regimes in the Oued Reghaya sub-watershed, a vital
tributary of the Tensift River in the semi-arid High Atlas region of Morocco. Given the increasing pressure from climate
change and local water demands, understanding the evolution of low-flow events is critical for sustainable water resource
management. We analyze 55 years of monthly discharge data (1963–2018) from the Tahanaout hydrometric station using
the annual minimum monthly flow index (QMNA) and the Cumulative Sum (CUSUM) technique. While QMNA reveals
historical trends in flow minima, CUSUM analysis enables the identification of abrupt shifts and regime changes in
hydrological behavior. Results show significant downward trends in low-flows, with critical transition points in the late
1980s and post-2000s, coinciding with increased climatic variability and regional population pressure. The analysis further
identifies the months most frequently associated with low-flows, offering insight into seasonal vulnerability. This study
emphasizes the importance of combining traditional hydrological indices with change-point detection methods like
CUSUM to enhance climate-resilient water planning in semi-arid mountainous regions
KEY WORDS: Low-flows, QMNA, CUSUM, climate change, Oued Reghaya
Address:
- Bahija CHOUKRI, Sultan Moulay Slimane University, B.P. 524, Beni Mellal, Morocco (Corresponding author. Tel.: Fax.: Email: choukribahijastu@gmail.com)
- Omaima ELKBICHI, Sultan Moulay Slimane University, B.P. 524, Beni Mellal, Morocco
- Elhoucein LAYATI, Sultan Moulay Slimane University, B.P. 524, Beni Mellal, Morocco
- Mohamed EL GHACHI, Sultan Moulay Slimane University, B.P. 524, Beni Mellal, Morocco
Acta Hydrologica Slovaca, Vol. 26, No. 2, 2025, p. 387 - 397, doi: 10.31577/ahs-2025-0026.02.0039
Scientific Paper, English
Anna LIOVÁ, Roman VÝLETA, Kamila HLAVČOVÁ, Katarína JENEIOVÁ, Milan ONDERKA, Ján SZOLGAY: Transposition of donor daily flows to ungauged catchments for reservoir safety
analysis using drainage area-based multipliers
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- Daily discharge series are essential for water allocation, ecological flow assessment, hydropower planning, and flood risk
management. Estimating daily streamflow at locations without gauges remains a recurring need in hydrological practice.
Where process-based models cannot be calibrated, or data are insufficient for regional parameter transfer, a pragmatic
alternative is to transpose the observed daily hydrograph from a hydrologically similar, gauged donor site to the ungauged
target catchment. One of the most widely used families of such transposition techniques relies on drainage area-based
multipliers (DAR), under the premise that discharge scales with contributing area when other controls are broadly
comparable. This paper provides a methodological description for estimating continuous daily streamflow at ungauged
target catchments by transposing scaled donor gauge hydrographs. We summarize the underlying assumptions,
mathematical formulations, and two practical implementations of the DAR principle are compared in estimating lateral
inflows into the Liptovská Mara reservoir. The results indicate minimal differences between the principles, implying that
simpler methods may be sufficient for practical applications in water management while maintaining reliable estimates of
streamflow. The findings highlight the practical advantage of requiring discharge data only from the main river, which is
particularly valuable where tributary measurements are unavailable. The approach demonstrated here for Liptovská Mara
can be applied to other ungauged catchments, supporting more efficient hydrological assessments in reservoir
management and flood protection planning. More broadly, the paper highlights the potential of simple and transferable
principles to support sustainable water management and adaptation strategies responding to changes in regions where
hydrological observations remain limited.
KEY WORDS: ungauged catchments; drainage-area ratio; donor transposition; daily flow hydrographs, regionalization
Address:
- Anna LIOVÁ, Department of Land and Water Resources Management, Faculty of Civil Engineering, Slovak University of Technology in Bratislava, Radlinského 11, 810 05 Bratislava, Slovak Republic (Corresponding author. Tel.: Fax.: Email: anna.liova@stuba.sk)
- Roman VÝLETA, Department of Land and Water Resources Management, Faculty of Civil Engineering, Slovak University of Technology in Bratislava, Radlinského 11, 810 05 Bratislava, Slovak Republic
- Kamila HLAVČOVÁ, Department of Land and Water Resources Management, Faculty of Civil Engineering, Slovak University of Technology in Bratislava, Radlinského 11, 810 05 Bratislava, Slovak Republic
- Katarína JENEIOVÁ, Slovak Hydrometeorological Institute
Jeséniova 17, 833 15 Bratislava, Slovak Republic
- Milan ONDERKA, Regional Climatological Institute, 900 68 Plavecký Štvrtok 794, Slovak Republic
- Ján SZOLGAY, Department of Land and Water Resources Management, Faculty of Civil Engineering, Slovak University of Technology in Bratislava, Radlinského 11, 810 05 Bratislava, Slovak Republic
Acta Hydrologica Slovaca, Vol. 26, No. 2, 2025, p. 398 - 405, doi: 10.31577/ahs-2025-0026.02.0040
Scientific Paper, English
Omaima ELKBICHI, Elhoucein LAYATI, Mohamed EL GHACHI: Assessing the relationship between rainfall variability and flow dynamics in the Lakhdar
River Basin (Oum Er-Rabia basin – Morocco) under of climate change
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- In the context of water resource management, which is influenced by climate variability, especially at the qualitative level,
it is crucial to study the hydrological functioning of the catchment area. the study of the hydrological functioning of
the catchment area is crucial for developing adaptation strategies. The aim of this work is to gain a good understanding of
the hydrological functioning of the Oued Lakhdar watershed, which is located to the south of Azilal, to the east of Demnat
and to the west of Zawyat Ahançal.is a tributary of the Oum Er Rbia basin. This study is based on a statistical
methodology, to analyse the flow of the basin across several temporal scales, and to determine the hydrological regime of
the wadi. We will then carry out a frequency analysis, which is a very important statistical method, using hydrometric
data from the Addemaghne and Sgatt stations. during the chronic series (1986–2021). The results obtained show that
the flow of the wadi varies from one year to the next. High values are recorded in winter and low values in summer. So
to improve the fragility of the water resources in this basin and manage them properly, we need to limit the overexploitation of surface and groundwater.
KEY WORDS: Lakhdar River Bassin, climate change, hydrological functioning, hydrological regime, management
Address:
- Omaima ELKBICHI, Landscape Dynamics, Risks, and Heritage Laboratory, Sultan Moulay Slimane University, Faculty of Letters and Human Sciences, Beni Mellal, Morocco (Corresponding author. Tel.: Fax.: Email: omaymaelkbichi@gmail.com)
- Elhoucein LAYATI, Landscape Dynamics, Risks, and Heritage Laboratory, Sultan Moulay Slimane University, Faculty of Letters and Human Sciences, Beni Mellal, Morocco
- Mohamed EL GHACHI, Landscape Dynamics, Risks, and Heritage Laboratory, Sultan Moulay Slimane University, Faculty of Letters and Human Sciences, Beni Mellal, Morocco